While
a majority of the body's cholesterol is produced in the liver, red
yeast rice has been shown to effectively restrict the livers'
production. However, this herbal compound also contains a variety of
ingredients and active constituents that have been shown in studies
to impart healthful cholesterol benefits. One active constituent,
monacolin K, may effectively stop a key liver enzyme from producing
cholesterol. A study published in 1997 in the journal Current
Therapeutic Research found that men and women taking 13.5 mg total
monacolins (about 1.2 grams) of concentrated red yeast rice daily for
two months showed significant decreases in serum (blood) cholesterol
levels. A UCLA School of Medicine clinical trial found that
supplementation of about 10 mg total monacolins (2.4 grams) daily of
red yeast rice for 12 weeks significantly decreased total and LDL
("bad") cholesterol levels, as well as triglycerides in a
sample of people with elevated cholesterol.
Another
cholesterol-boosting ingredient in red yeast rice, the compound known
as mevinolin, has also been shown to offer antioxidant properties. In
addition, the cholesterol benefits of red yeast rice may be due to
its large amounts of such ingredients as fiber, rice starch, sterols,
and fatty acids, all of which have been shown to decrease harmful
levels of cholesterol and triglycerides, while also raising levels of
HDL ("good") cholesterol.
In
addition to rice starch, protein, fiber,
sterols, and fatty acids, red yeast rice contains numerous active
constituents, including monacolin K, dihydromonacolin, and monacolin
I to VI.
Researchers
have determined that one of the ingredients in red yeast rice, called
monacolin K, inhibits the production of cholesterol
by stopping the action of a key enzyme in the liver ( HMG-CoA
reductase) that is responsible for manufacturing cholesterol. The
drug lovastatin
(Mevacor®) acts in a similar fashion to this red yeast rice
ingredient. However, the amount per volume of monacolin K in red
yeast rice is small (0.2% per 5 mg) when compared to the 20–40 mg
of lovastatin available as a prescription drug. This has prompted
researchers to suggest that red yeast rice may have other
ingredients, such as sterols, that might also contribute to lowering
cholesterol.
(Heber
D, Yip I, Ashley JM, et al. Cholesterol-lowering effects of a
proprietary Chinese red-yeast-rice dietary supplement. Am
J Clin Nutr
1999;69:231–6). |
